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PropertyHandle :: ExtractSortKey - Extract sort key value

The function extracts the key value according to the current sort order (index).

When no instance has been passed the function extracts the key from the currently selected instance. If no instance has been selected in the property handle the function will select the instance located in the property handle. When no instance could be selected an no instance has been passed the function returns an empty key.

When a key area has been passed in the key parameter the function returns the key in the passed key area. When no key or an empty key has been passed the returned key area refers to an internal area, which should not be modified by the application. This area is valid until the next ODABA interface function has been called.

Return value:  Key value (   )

The key is provided in the internal key format. When necessary the key value can be converted to a string using the ({.r pib.KeyToString}()) function.

Implementation overview

Implementation details

  1. - internal feature (not documented)
    ::Key PropertyHandle  :: ExtractSortKey ( ::Key sort_key, ::Instance instance )
    • sort_key - - internal feature (not documented)
    • instance - Instance area

      Instances do have the type of the referenced property handle (collection type). The instance contains a pointer to a properly structured instance area.

      You can use the !-operator or the GetData() function to check whether the instance refers to data or not.

  2. to list
  3. - internal feature (not documented)
    ::Key PropertyHandle  :: ExtractSortKey ( ::Key sort_key_w=Key() )
    • sort_key_w - Sort key value

      The key is provided in the internal key format. When necessary the key value can be converted from a string into the internal format using the StringToKey() function.

      Default: Key()
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